Rotatable medical device

ABSTRACT

A rotational atherectomy device advanceable over a guidewire. The rotational atherectomy device includes a drive shaft rotatably extending through an outer tubular member to rotate a cutting member positioned at a distal end thereof. The rotational atherectomy device further includes an insert positioned within the cutting member for frictional contact with the guidewire.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to U.S.Provisional Application Ser. No. 62/087,531, filed Dec. 4, 2014, theentirety of which is incorporated herein by reference.

TECHNICAL FIELD

The disclosure is directed to devices and methods for removing occlusivematerial from a body lumen. More particularly, the disclosure isdirected to a rotational atherectomy device for forming a passagewaythrough an occlusion of a body lumen, such as a blood vessel.

BACKGROUND

Many patients suffer from occluded arteries and other blood vesselswhich restrict blood flow. Occlusions can be partial occlusions thatreduce blood flow through the occluded portion of a blood vessel ortotal occlusions (e.g., chronic total occlusions) that substantiallyblock blood flow through the occluded blood vessel. Revascularizationtechniques include using a variety of devices to pass through theocclusion to create or enlarge an opening through the occlusion.Atherectomy is one technique in which a catheter having a rotatablecutting element thereon is advanced through the occlusion to form orenlarge a pathway through the occlusion. Typically, a guidewire isinitially placed across the occlusion and then the atherectomy catheteris advanced over the guidewire as the atherectomy catheter is passedthrough the occlusion.

A need remains for alternative atherectomy devices to facilitatecrossing an occlusion while being advanced along a guidewire.

BRIEF SUMMARY

The disclosure is directed to several alternative designs, materials andmethods of manufacturing medical device structures and assemblies, anduses thereof.

Accordingly, one illustrative example is a rotational atherectomydevice. The rotational atherectomy device includes an outer tubularmember having a lumen extending therethrough, a cutting memberrotationally positioned at a distal end of the outer tubular member, anda drive shaft extending through the lumen of the outer tubular member.The drive shaft is rotatable relative to the outer tubular member torotate the cutting member. The rotational atherectomy device furtherincludes an insert positioned within the cutting member, the insertincluding an opening extending therethrough for passing a guidewiretherethrough.

Additionally or alternatively, a distal portion of the drive shaftextends into a bore of the cutting member.

Additionally or alternatively, the insert is positioned in the bore ofthe cutting member distal of a distal end of the drive shaft.

Additionally or alternatively, the drive shaft includes a guidewirelumen extending therethrough axially aligned with the opening of theinsert.

Additionally or alternatively, the guidewire lumen has a diameter andthe opening of the insert has a diameter less than the diameter of theguidewire lumen.

Additionally or alternatively, the insert includes an inner surfacedefining the opening of the insert, wherein at least a portion of theinner surface is nonparallel to a central longitudinal axis of the driveshaft.

Additionally or alternatively, the inner surface tapers radially outwardfrom the central longitudinal axis in a distal direction.

Additionally or alternatively, the inner surface tapers radially outwardin a distal direction from a mid region of the insert to a distal tip ofthe insert.

Additionally or alternatively, the inner surface tapers radially outwardin a proximal direction from the mid region of the insert to a proximalend of the insert.

Additionally or alternatively, the bore has a diameter greater than thediameter of the opening of the insert.

Additionally or alternatively, the insert includes an inner surfacedefining the opening of the insert, the inner surface having a surfaceroughness R_(a) of 0.4 micrometers or less.

Additionally or alternatively, the insert includes an inner surfacedefining the opening of the insert, the inner surface having a surfaceroughness R_(a) of 0.2 micrometers or less.

Additionally or alternatively, the cutting member includes a distalopening axially aligned with the opening of the insert, the distalopening of the cutting member having a diameter greater than or equal toa diameter of the opening of the insert.

Additionally or alternatively, the insert is formed of a polymericmaterial.

Additionally or alternatively, the insert is formed of a polishedmetallic material.

An illustrative example that may optionally be used in conjunction withany of the above described characteristics is a rotational atherectomydevice. The rotational atherectomy device includes an outer tubularmember having a lumen extending therethrough, a cutting memberrotationally positioned at a distal end of the outer tubular member, anda drive shaft extending through the lumen of the outer tubular member.The cutting member includes a central longitudinal bore extendingtherethrough. A distal end region of the drive shaft extends into thebore of the cutting member. The drive shaft is rotatable relative to theouter tubular member to rotate the cutting member. The rotationalatherectomy device further includes an insert positioned within the boreof the cutting member. The insert includes an opening extendingtherethrough axially aligned with the bore of the cutting member.

Additionally or alternatively, the drive shaft includes a guidewirelumen extending therethrough axially aligned with the opening of theinsert.

Additionally or alternatively, the guidewire lumen has a diameter andthe opening of the insert has a diameter less than the diameter of theguidewire lumen.

Additionally or alternatively, the cutting member includes a distalopening axially aligned with the opening of the insert, the distalopening of the cutting member having a diameter greater than or equal toa diameter of the opening of the insert.

Additionally or alternatively, the insert includes an inner surfacedefining the opening of the insert, wherein at least a portion of theinner surface is nonparallel to a central longitudinal axis of the driveshaft.

Additionally or alternatively, the insert includes an inner surfacedefining the opening of the insert, the inner surface having a surfaceroughness R_(a) of 0.4 micrometers or less.

Another illustrative example is method of creating or enlarging apassageway through an occlusion in a body lumen. The method includesadvancing a guidewire through a body lumen to a location proximate anocclusion and then advancing a rotational atherectomy device through thebody lumen over the guidewire to a location proximal of the occlusion inthe body lumen. The rotational atherectomy device includes a rotatabledrive shaft extending through an outer tubular member to rotatably drivea cutting member positioned at a distal end of the outer tubular member,and an insert positioned within the cutting member. The guidewireextends through an opening of the insert and a guidewire lumen of thedrive shaft. The method further includes rotating the cutting memberrelative to the guidewire with the drive shaft while advancing thecutting member through the occlusion.

Additionally or alternatively, a coefficient of static friction betweenthe insert and the guidewire is less than 0.25.

Additionally or alternatively, a coefficient of static friction betweenthe insert and the guidewire is less than 0.10.

BRIEF DESCRIPTION OF THE DRAWINGS

The aspects of the disclosure may be more completely understood inconsideration of the following detailed description of variousembodiments in connection with the accompanying drawings, in which:

FIG. 1 illustrates an exemplary atherectomy system;

FIG. 2 is a cross-sectional view of a distal portion of an exemplaryatherectomy system in accordance with the disclosure;

FIG. 3 is a cross-sectional view of a distal portion of anotherexemplary atherectomy system in accordance with the disclosure;

FIG. 4 is a cross-sectional view of a distal portion of anotherexemplary atherectomy system in accordance with the disclosure;

FIG. 5 is a cross-sectional view of a distal portion of anotherexemplary atherectomy system in accordance with the disclosure; and

FIGS. 6-12 illustrate aspects of an exemplary method of traversing anocclusion in a blood vessel.

While the aspects of the disclosure are amenable to variousmodifications and alternative forms, specifics thereof have been shownby way of example in the drawings and will be described in detail. Itshould be understood, however, that the intention is not to limitaspects of the disclosure to the particular embodiments described. Onthe contrary, the intention is to cover all modifications, equivalents,and alternatives falling within the spirit and scope of the disclosure.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

Definitions of certain terms are provided below and shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about”, whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the term “about” may be indicative asincluding numbers that are rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4,and 5).

Although some suitable dimensions, ranges and/or values pertaining tovarious components, features and/or specifications are disclosed, one ofskill in the art, incited by the present disclosure, would understanddesired dimensions, ranges and/or values may deviate from thoseexpressly disclosed.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include or otherwise refer to singular aswell as plural referents, unless the content clearly dictates otherwise.As used in this specification and the appended claims, the term “or” isgenerally employed to include “and/or,” unless the content clearlydictates otherwise.

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The detailed description and the drawings, which are notnecessarily to scale, depict illustrative embodiments and are notintended to limit the scope of the disclosure. The illustrativeembodiments depicted are intended only as exemplary. Selected featuresof any illustrative embodiment may be incorporated into an additionalembodiment unless clearly stated to the contrary.

An exemplary rotational atherectomy system 10 is shown in FIG. 1. Therotational atherectomy system 10 may include a rotational atherectomydevice 12 and a controller 14 for controlling the rotational atherectomydevice 12. The rotational atherectomy device 12 may include a housing 16and an elongate shaft 18 extending distally from the housing 16 to acutting member 20 located at a distal end of the elongate shaft 18. Theelongate shaft 18 may include a drive shaft 24 to provide rotationalmotion to the cutting member 20. In some instances, the elongate shaft18 may include an outer tubular member 22 having a lumen extendingtherethrough and the drive shaft 24 may extend through the lumen of theouter tubular member 22. The drive shaft 24, which may be fixed to thecutting member 20, may be rotatable relative to the outer tubular member22 to rotate the cutting member 20. In some instances the axial positionof the cutting member 20 relative to the outer tubular member 22 may beadjusted by moving the drive shaft 24 longitudinally relative to theouter tubular member 22. For example, the atherectomy device 12 mayinclude an advancer assembly 26 positioned in the housing 16, orotherwise provided with the housing 16, that is longitudinally movablerelative to the housing 16. The outer tubular member 22 may be coupledto the housing 16 while the drive shaft 24 may be coupled to theadvancer assembly 26. Accordingly, the drive shaft 24 (and thus thecutting member 20) may be longitudinally movable relative to the outertubular member 22 by actuating the advancer assembly 26 relative to thehousing 16.

The rotational atherectomy device 12 may include a prime mover (notshown) to provide rotational motion to the drive shaft 24 to rotate thecutting member 20. For example, in some instances the prime mover may bea fluid turbine within the housing 16, such as provided with theadvancer assembly 26. In other instances, however, the prime mover maybe an electrical motor, or the like. The controller 14 may be used tocontrol the prime mover. For example, the user may provide power to theprime mover and/or control the speed of rotation of the drive shaft 24via the controller 14. For example, the front panel 28 of the controller14 may include a user interface including a power switch, speed controlmechanism (e.g., a speed control knob and/or buttons), a display, and/orother features for controlling the rotational atherectomy device 12. Insome instances, the rotational atherectomy system 10 may include aremote control device 30, such as a foot pedal, a hand control, or othermechanism which may be used to control the power and/or speed to theprime mover, for example.

In instances in which the prime mover is a turbine, the rotationalatherectomy system 10 may also include a pressurized fluid source 32providing a pressurized fluid to the turbine to rotate the drive shaft24. In some instances, as shown, the pressurized fluid source 32 may bea tank of pressurized fluid (e.g., compressed air), which may or may notinclude an air compressor. In other instances, the pressured fluidsource 32 may be provided external of the rotational atherectomy system10, such as from a wall outlet at the medical facility. The pressuredfluid source 32 may be coupled to the controller 14 via a fluid conduit34, which in turn is coupled to the rotational atherectomy device 12 viaa fluid conduit 36. The controller 14 may regulate the flow and/orpressure of fluid through the fluid conduit 36 to the rotationalatherectomy device 12 to control the speed of rotation of the driveshaft 24 and cutting member 20, for instance.

In instances in which the prime mover is an electric motor, the electricmotor may be coupled to the controller 14 via an electrical connectionto control the electric motor and/or provide electricity to the electricmotor.

In some instances, the rotational atherectomy device 12 may include aspeed sensor, such as an optical speed sensor, coupled to the controller14 via a connector 38, such as a fiber optic connector to provide speeddata to the controller 14. In other instances, an electronic sensor,such as a Hall Effect sensor, or other type of sensor may be used tosense the speed of the drive shaft 24 and cutting member 20. The speeddata may be displayed, such as on the front panel 28 and/or thecontroller 14, and/or used to control the speed of the cutting member20, such as maintaining a desired speed of the cutting member 20 duringa medical procedure.

In some embodiments, the rotational atherectomy system 10 may beconfigured to infuse fluid through the elongate shaft 18 to thetreatment site and/or aspirate fluid through the elongate shaft 18 fromthe treatment site. For example, the rotational atherectomy system 10may include a fluid supply 40 for providing a flow of fluid through alumen of the elongate shaft 18 to a treatment site. As shown in FIG. 1,in some instances the fluid supply 40 may include a saline bag 42 whichmay be pressurized by a pressure cuff 44 to provide a pressurized fluid(e.g., saline) to the rotational atherectomy device 12 through a fluidsupply line 46. In other embodiments, an infusion pump, such as aperistaltic pump, may be used to deliver pressurized fluid to therotational atherectomy device 12. Additionally or alternatively, in someembodiments the rotational atherectomy system 10 may be configured toaspirate fluid from the treatment site. For example, the rotationalatherectomy system 10 may include an aspiration pump, such as aperistaltic pump, to generate a vacuum to aspirate fluid through a lumenof the elongate shaft 18 to a fluid collection container (not shown), ifdesired.

In some instances, the elongate shaft 18 of the rotational atherectomydevice 12 may be advanced over a guidewire 48 to a treatment site. Forexample, the drive shaft 24 may include a guidewire lumen through whichthe guidewire 48 may pass. Additionally or alternatively, the elongateshaft 18 may be advanced through a lumen of a guide catheter to atreatment site.

The distal region of the rotational atherectomy device 12 is shown inFIG. 2. As shown, the drive shaft 24, which in some instances mayinclude a coiled member, may extend through the lumen 72 of the outertubular member 22 and be rotationally and/or longitudinally movablerelative to the outer tubular member 22. The drive shaft 24 may includethe cutting member 20 mounted thereon. In some instances, the cuttingmember 20 may be a burr having an abrasive surface, such as a diamondcoated abrasive surface. In other instances, the cutting member 20 mayinclude one or more flutes having a cutting edge, or the cutting member20 may be of another construction for abrading or cutting occlusivematerial.

A guidewire lumen 60 may extend through the drive shaft 24 and thecutting member 20 to a distal tip 70 of the cutting member 20. As shown,the cutting member 20 may include a bore 62 extending therethrough witha distal end region of the drive shaft 24 extending into the bore 62 ofthe cutting member 20.

The rotational atherectomy device 12 may also include an insert 50positioned within the cutting member 20. For example, the insert 50 maybe positioned in the bore 62 of the cutting member 20 distal of a distalend 25 of the drive shaft 24. The insert 50 may include an opening 52extending therethrough for passing the guidewire 48 therethrough. Insome instances, the opening 52 through the insert 50 may be axiallyaligned with the guidewire lumen 60 of the drive shaft 24. In otherwords, the opening 52 may be coaxial with the guidewire lumen 60 in someinstances.

The guidewire lumen 60 may have a diameter D₁ and the opening 52 throughthe insert 50 may have a diameter D₂. In some instances, the diameter D₁of the guidewire lumen 60 may be greater than the diameter D₂ of theopening 52. Accordingly, there may be a closer tolerance between aninner surface of the insert 50 and the guidewire 48 than the tolerancebetween the guidewire 48 and the drive shaft 24. In other words, theremay be greater clearance between the guidewire 48 and the inner surfaceof the drive shaft 24 than the clearance between the guidewire 48 andthe inner surface of the insert 50 defining the opening 52. For example,to accommodate a guidewire having an outer diameter of 0.36 millimeter(0.014 inches), the guidewire lumen 60 may have a diameter D₁ of about0.41 millimeters (0.016 inches) or more, or about 0.46 millimeters(0.018 inches) or more, while the diameter D₂ of the opening 52 of theinsert 50 may be about 0.38 millimeters (0.015 inches).

The bore 62, within which the insert 50 and/or the distal end region ofthe drive shaft 24 may be disposed, may have a diameter D₃. The diameterD₃ of the bore 62 may be greater than the diameter D₁ of the guidewirelumen 60 through the drive shaft 24 and/or the opening 52 through theinsert 50. In some instances, the insert 50 may be inserted into thebore 62 of the cutting member 20 from the proximal opening of thecutting member 20. Thereafter, the distal end region of the drive shaft24 may be inserted into the bore 62 of the cutting member 20 from theproximal opening of the cutting member 20. In some instances, the distalend 25 of the drive shaft 24 may face or abut the proximal end of theinsert 50 within the bore 62 of the cutting member 20.

The cutting member 20 may include a distal opening at the distal tip 70of the cutting member 20. The distal opening of the cutting member 20may be axially aligned with the opening 52 of the insert 50. In someinstances, the distal opening of the cutting member 20 may have adiameter greater than or equal to the diameter D₂ of the opening 52 ofthe insert 50. In some instances, the distal opening of the cuttingmember 20 may be configured to facilitate inserting the guidewire 48into the opening 52 of the insert 50 and through the guidewire lumen 62of the drive shaft 24 from the distal tip 70 of the cutting member 20.

In some instances, the insert 50 may function as a spacer and/or bearingbetween the cutting member 20 and the guidewire 48. For example, theinsert 50 may provide a low friction interface with the guidewire 48 asthe cutting member 20 is rotatably driven during a medical procedure.

In some instances, the inner surface of the insert 50 which defines theopening 52 of the insert 50 may have an average surface roughness R_(a)of about 0.4 micrometers or less, about 0.3 micrometers or less, about0.2 micrometers or less, or about 0.1 micrometers or less. Additionallyor alternatively, in some instances the coefficient of static frictionμ_(s) between the insert 50 and the guidewire 48 may be less than 0.25,less than 0.20, less than 0.15 or less than 0.10, for example.

The insert 50 may be made of any desired material, such as a lowfriction material, including a metallic material, a polymeric material,or a combination thereof. Some suitable metallic materials includestainless steel, such as highly polished stainless steel. Some suitablepolymeric materials include polyamide (e.g., nylon),polytetrafluoroethylene (PTFE), high density polyethylene (HDPE),ultra-high molecular weight polyethylene (UHMWPE), or other polymericmaterial having a high molecular weight, for example.

Another embodiment of the distal region of the rotational atherectomydevice 12 is shown in FIG. 3. The components and arrangement of thedistal region may be similar in many respects to that shown in FIG. 2,and thus reference to those aspects discussed above is noted. As shownin FIG. 3, an insert 150 may be positioned within the cutting member 20.For example, the insert 150 may be positioned in the bore 62 of thecutting member 20 distal of a distal end 25 of the drive shaft 24. Theinsert 150 may include an opening 152 extending therethrough for passingthe guidewire 48 therethrough. In some instances, the opening 152through the insert 150 may be axially aligned with the guidewire lumen60 of the drive shaft 24. In other words, the opening 152 may be coaxialwith the guidewire lumen 60 in some instances.

The insert 150 may include an inner surface defining the opening 152 ofthe insert 150. As shown in FIG. 3, at least a portion of the innersurface of the insert 150 may be nonparallel to the central longitudinalaxis X of the drive shaft 24. For example, the inner surface of theinsert 150 may taper radially outward from the central longitudinal axisin a distal direction (i.e., flare radially outward toward the distaltip 70) along at least a portion of the longitudinal length of theopening 152. For example, a proximal region and/or mid region of theopening 152 may have a diameter D₂, while a distal region of the opening152 may have a diameter D₄ greater than the diameter D₂ of the proximalregion and/or mid region of the opening 152.

The insert 150 may be similar to the insert 50 described above. Forexample, the insert 150 may function as a spacer and/or bearing betweenthe cutting member 20 and the guidewire 48. For example, the insert 150may provide a low friction interface with the guidewire 48 as thecutting member 20 is rotatably driven during a medical procedure.

In some instances, the inner surface of the insert 150 which defines theopening 152 of the insert 150 may have an average surface roughnessR_(a) of about 0.4 micrometers or less, about 0.3 micrometers or less,about 0.2 micrometers or less, or about 0.1 micrometers or less.Additionally or alternatively, in some instances the coefficient ofstatic friction μ_(s) between the insert 150 and the guidewire 48 may beless than 0.25, less than 0.20, less than 0.15 or less than 0.10, forexample.

The insert 150 may be made of any desired material, such as a lowfriction material, including a metallic material, a polymeric material,or a combination thereof. Some suitable metallic materials includestainless steel, such as highly polished stainless steel. Some suitablepolymeric materials include polyamide (e.g., nylon),polytetrafluoroethylene (PTFE), high density polyethylene (HDPE),ultra-high molecular weight polyethylene (UHMWPE), or other polymericmaterial having a high molecular weight, for example.

Also shown in FIG. 3, the distal opening of the cutting member 20 at thedistal tip 70 may have a diameter D₅ greater than the diameter D₄ of thedistal region of the opening 152, and thus greater than the diameter D₂of the proximal region and/or mid region of the opening 152. Theenlarged diameter of the distal opening of the cutting member 20 mayfacilitate inserting the guidewire 48 into the opening 152 of the insert150 and through the guidewire lumen 62 of the drive shaft 24 from thedistal tip 70 of the cutting member 20.

Another embodiment of the distal region of the rotational atherectomydevice 12 is shown in FIG. 4. The components and arrangement of thedistal region may be similar in many respects to that shown in FIG. 2,and thus reference to those aspects discussed above is noted. As shownin FIG. 4, an insert 250 may be positioned within the cutting member 20.For example, the insert 250 may be positioned in the bore 62 of thecutting member 20 distal of a distal end 25 of the drive shaft 24. Theinsert 250 may include an opening 252 extending therethrough for passingthe guidewire 48 therethrough. In some instances, the opening 252through the insert 250 may be axially aligned with the guidewire lumen60 of the drive shaft 24. In other words, the opening 252 may be coaxialwith the guidewire lumen 60 in some instances.

The insert 250 may include an inner surface defining the opening 252 ofthe insert 250. As shown in FIG. 4, at least a portion of the innersurface of the insert 250 may be nonparallel to the central longitudinalaxis X of the drive shaft 24. For example, the inner surface of theinsert 250 may taper radially outward from the central longitudinal axisin a distal direction (i.e., flare radially outward toward the distaltip 70) along at least a portion of the longitudinal length of theopening 252. For example, a mid region of the opening 252 may have adiameter D₂, while a distal region of the opening 252 may have adiameter D₄ greater than the diameter D₂ of the mid region of theopening 252. Furthermore, the inner surface of the insert 250 may taperradially outward from the central longitudinal axis in a proximaldirection (i.e., flare radially outward toward the proximal end of theinsert 250) along at least a portion of the longitudinal length of theopening 252. For example, a proximal region of the opening 252 may havea diameter D₆ greater than the diameter D₂ of the mid region of theopening 252. In some instances the diameter D₆ of the proximal region ofthe opening 252 may be the same as the diameter D₄ of the distal regionof the opening 252, or the diameter D₆ may be different than (e.g.,greater than or less than) the diameter D₄.

The insert 250 may be similar to the insert 50 described above. Forexample, the insert 250 may function as a spacer and/or bearing betweenthe cutting member 20 and the guidewire 48. For example, the insert 250may provide a low friction interface with the guidewire 48 as thecutting member 20 is rotatably driven during a medical procedure.

In some instances, the inner surface of the insert 250 which defines theopening 252 of the insert 250 may have an average surface roughnessR_(a) of about 0.4 micrometers or less, about 0.3 micrometers or less,about 0.2 micrometers or less, or about 0.1 micrometers or less.Additionally or alternatively, in some instances the coefficient ofstatic friction μ_(s) between the insert 250 and the guidewire 48 may beless than 0.25, less than 0.20, less than 0.15 or less than 0.10, forexample.

The insert 250 may be made of any desired material, such as a lowfriction material, including a metallic material, a polymeric material,or a combination thereof. Some suitable metallic materials includestainless steel, such as highly polished stainless steel. Some suitablepolymeric materials include polyamide (e.g., nylon),polytetrafluoroethylene (PTFE), high density polyethylene (HDPE),ultra-high molecular weight polyethylene (UHMWPE), or other polymericmaterial having a high molecular weight, for example.

Also shown in FIG. 4, the distal opening of the cutting member 20 at thedistal tip 70 may have a diameter D₅ greater than the diameter D₄ of thedistal region of the opening 252, and thus greater than the diameter D₂of the mid region of the opening 252. The enlarged diameter of thedistal opening of the cutting member 20 may facilitate inserting theguidewire 48 into the opening 252 of the insert 250 and through theguidewire lumen 62 of the drive shaft 24 from the distal tip 70 of thecutting member 20.

Another embodiment of the distal region of the rotational atherectomydevice 12 is shown in FIG. 5. The components and arrangement of thedistal region may be similar in many respects to that shown in FIG. 2,and thus reference to those aspects discussed above is noted. As shownin FIG. 5, an insert 350 may be positioned within the cutting member 20.For example, the insert 350 may be positioned in the bore 62 of thecutting member 20 within the distal end region of the drive shaft 24.The insert 350 may include an opening 352 extending therethrough forpassing the guidewire 48 therethrough. In some instances, the opening352 through the insert 350 may be axially aligned with the guidewirelumen 60 of the drive shaft 24. In other words, the opening 352 may becoaxial with the guidewire lumen 60 in some instances.

The insert 350 may include an inner surface defining the opening 352 ofthe insert 350. As shown in FIG. 5, at least a portion of the innersurface of the insert 350 may be nonparallel to the central longitudinalaxis X of the drive shaft 24. For example, the inner surface of theinsert 350 may taper radially outward from the central longitudinal axisin a distal direction (i.e., flare radially outward toward its distalend) along at least a portion of the longitudinal length of the opening352 and/or may taper radially outward from the central longitudinal axisin a proximal direction (i.e., flare radially outward toward itsproximal end). For example, a mid region of the opening 352 may have adiameter D₂, while a proximal region and/or a distal region of theopening 352 may have a diameter greater than the diameter D₂ of the midregion of the opening 352.

The insert 350 may be similar to the insert 50 described above. Forexample, the insert 350 may function as a spacer and/or bearing betweenthe cutting member 20 and the guidewire 48. For example, the insert 350may provide a low friction interface with the guidewire 48 as thecutting member 20 is rotatably driven during a medical procedure.

In some instances, the inner surface of the insert 350 which defines theopening 352 of the insert 350 may have an average surface roughnessR_(a) of about 0.4 micrometers or less, about 0.3 micrometers or less,about 0.2 micrometers or less, or about 0.1 micrometers or less.Additionally or alternatively, in some instances the coefficient ofstatic friction μ_(s) between the insert 350 and the guidewire 48 may beless than 0.25, less than 0.20, less than 0.15 or less than 0.10, forexample.

The insert 350 may be made of any desired material, such as a lowfriction material, including a metallic material, a polymeric material,or a combination thereof. Some suitable metallic materials includestainless steel, such as highly polished stainless steel. Some suitablepolymeric materials include polyamide (e.g., nylon),polytetrafluoroethylene (PTFE), high density polyethylene (HDPE),ultra-high molecular weight polyethylene (UHMWPE), or other polymericmaterial having a high molecular weight, for example.

Also shown in FIG. 5, the distal opening of the cutting member 20 at thedistal tip 70 may have a diameter D₅ greater than the diameter D₂ of theopening 352. The enlarged diameter of the distal opening of the cuttingmember 20 may facilitate inserting the guidewire 48 into the opening 352of the insert 350 and through the guidewire lumen 62 of the drive shaft24 from the distal tip 70 of the cutting member 20.

As shown in FIG. 5, the bore 62 of the cutting member 20 may include astepped region between the diameter D₃ and the diameter D₄. In someinstances, the distal end 25 of the drive shaft 24 and/or the distal endof the insert 350 may be positioned adjacent to and/or abut the steppedregion of the bore 62.

Although the central longitudinal axis of the cutting member 20 and thecentral longitudinal axis of the insert 50, 150, 250, 350 are shown inFIGS. 2-5 as being coaxial with the central longitudinal axis X (i.e.,the rotational axis) of the drive shaft 24, in other instances, thecentral longitudinal axis of the cutting member 20 and/or the centrallongitudinal axis of the insert 50, 150, 250, 350 may be non-coaxialwith the central longitudinal axis X of the drive shaft 24, allowing foreccentric rotation of the cutting member 20 while still providing asmooth bearing surface inside the cutting member 20 for the guidewire48.

Turning now to FIGS. 6-12, aspects of an exemplary method of traversingan occlusion in a blood vessel are shown. As shown in FIG. 6, aguidewire 48 may be advanced through the lumen 94 of the blood vessel 90to a location proximate an occlusion 92. For instance, the guidewire 48may be advanced through the occlusion 92 such that the distal end of theguidewire 48 passes distally beyond the occlusion 92.

Referring to FIG. 7, the rotational atherectomy device 12 may then beadvanced through the lumen 94 of the blood vessel 90 over the guidewire48 to a location proximate the occlusion 92 to create or enlarge apassageway through the occlusion 92. For instance, the elongate shaft 18of the rotational atherectomy device 12 may be advanced through a bodylumen (e.g., blood vessel 90) to a location proximal of the occlusion 92in the body lumen. For example, the guidewire 48 may pass into thedistal opening of the cutting member 20, through the opening 52, 152,252, 352 of the insert 50, 150, 250, 350 within the cutting member 20,and through the guidewire lumen 60 of the drive shaft 24, as shown inFIGS. 2-5. In some instances, the elongate shaft 18 may be advancedthrough a lumen of a guide catheter to the occlusion 92 while beingadvanced along the guidewire 48.

Once positioned proximate the occlusion 92, the rotational atherectomydevice 12 may be used to create or enlarge a passageway through theocclusion 92. For example, referring to FIG. 8, thereafter, rotation ofthe cutting member 20 (via rotationally driving the drive shaft 24) maybe initiated once the cutting member 20 has been advanced to theocclusion 92. The rotatable drive shaft 24 extending through the outertubular member 22 of the elongate shaft 18 of the rotational atherectomydevice 12 may be rotatably driven to rotatably drive the cutting member20 while advancing the cutting member 20 through the occlusion 92. Insome instances the drive shaft 24 may be advanced distally relative tothe outer tubular member 22 to advance the cutting member 20 through theocclusion 92, while in other instances the outer tubular member 22 maybe advanced together with the drive shaft 24. In some instances, fluidinfusion and/or fluid aspiration through one or more lumens of therotational atherectomy device 12 may be performed while advancing thecutting member 20 through the occlusion 92.

The insert 50, 150, 250, 350 may function as a bearing as the cuttingmember 20 rotates at a high rotational rate, e.g., 5,000 revolutions perminute (RPM) or more, 10,000 revolutions per minute (RPM) or more, or20,000 revolutions per minute (RPM) or more) about the guidewire 48. Theinsert 50, 150, 250, 350 may maintain the guidewire 48 spaced away fromdirectly contacting the cutting member 20 as the cutting member 20 isbeing rotated about its rotational axis. The frictional interactionbetween the guidewire 48 and the insert 50 may be less than that betweenthe guidewire 48 and the cutting member 20 if permitted to frictionallycontact one another. In some instances the coefficient of staticfriction μ_(s) between the insert 50, 150, 250, 350 and the guidewire 48may be less than 0.25, less than 0.20, less than 0.15 or less than 0.10,for example.

The cutting member 20 may be advanced through the occlusion 92 to formor enlarge a pathway 96 through the occlusion 92 to permit blood flowthrough the lumen 94 of the blood vessel 90, as shown in FIG. 9.Thereafter, as shown in FIG. 10, the rotational atherectomy device 12may be withdrawn, leaving the guidewire 48 in position across theocclusion 92. Another intravascular device, such as a therapeutic ordiagnostic medical device, may then be advanced over the guidewire 48 toa location proximate to or distal of the occlusion 92, for example. Forinstance, as shown in FIG. 11, an angioplasty catheter 100 may beadvanced over the previously positioned guidewire 48 to position aninflatable balloon 120 of the angioplasty catheter 100 across theocclusion 92. The balloon 120 may then be inflated with an inflationmedia introduced into the balloon 120 from an inflation lumen extendingthrough the elongate shaft 110 of the angioplasty catheter 100 tofurther enlarge the passageway through the occlusion 92.

As described above, the same guidewire 48 may be used throughout theprocedure without the need to exchange the guidewire 48 for one or moreother guidewires. For example, the same guidewire 48 used to initiallycross the occlusion 92 may also be used in advancing the rotationalatherectomy device 12 distally through the occlusion 92 and/or inadvancing one or more additional intravascular devices proximate to ordistally through the occlusion 92. The ability to utilize the sameguidewire 48 without performing a guidewire exchange may save timeduring the procedure as well as reduce the number of medical devicesneeded to complete the procedure.

It is noted that the rotational cutting devices described herein may beused in other medical procedures, such as in orthopedic medicalprocedures, if desired. For example, the penetrating member may bepenetrated into a bony structure to stabilize the cutting member priorto initiating engagement of the rotating cutting member with the bonystructure.

Those skilled in the art will recognize that aspects of the presentdisclosure may be manifested in a variety of forms other than thespecific embodiments described and contemplated herein. Accordingly,departure in form and detail may be made without departing from thescope and spirit of the present disclosure as described in the appendedclaims.

What is claimed is:
 1. A rotational atherectomy device, comprising: anouter tubular member having a lumen extending therethrough; a cuttingmember rotationally positioned at a distal end of the outer tubularmember; a drive shaft extending through the lumen of the outer tubularmember, the drive shaft rotatable relative to the outer tubular memberto rotate the cutting member; and an insert positioned within thecutting member, the insert including an opening extending therethroughfor passing a guidewire therethrough, wherein the insert includes aninner surface defining the opening of the insert, wherein at least aportion of the inner surface is nonparallel to a central longitudinalaxis of the drive shaft, wherein the inner surface tapers radiallyoutward from the central longitudinal axis in a distal direction,wherein the cutting member is fixed to the drive shaft.
 2. Therotational atherectomy device of claim 1, wherein a distal portion ofthe drive shaft extends into a bore of the cutting member.
 3. Therotational atherectomy device of claim 2, wherein the insert ispositioned in the bore of the cutting member distal of a distal end ofthe drive shaft.
 4. The rotational atherectomy device of claim 2,wherein the drive shaft includes a guidewire lumen extendingtherethrough longitudinally aligned with the opening of the insert. 5.The rotational atherectomy device of claim 4, wherein the guidewirelumen has a diameter and the opening of the insert has a diameter lessthan the diameter of the guidewire lumen.
 6. The rotational atherectomydevice of claim 1, wherein the inner surface tapers radially outward ina distal direction from a mid region of the insert to a distal tip ofthe insert.
 7. The rotational atherectomy device of claim 6, wherein theinner surface tapers radially outward in a proximal direction from themid region of the insert to a proximal end of the insert.
 8. Therotational atherectomy device of claim 1, wherein the cutting memberincludes a distal opening axially aligned with the opening of theinsert, the distal opening of the cutting member having a diametergreater than a diameter of the opening of the insert.
 9. The rotationalatherectomy device of claim 1, wherein the insert includes an innersurface defining the opening of the insert, the inner surface having asurface roughness R_(a) of 0.4 micrometers or less.
 10. The rotationalatherectomy device of claim 1, wherein the insert includes an innersurface defining the opening of the insert, the inner surface having asurface roughness R_(a) of 0.2 micrometers or less.
 11. A rotationalatherectomy device, comprising: an outer tubular member having a lumenextending therethrough; a cutting member rotationally positioned at adistal end of the outer tubular member, the cutting member including acentral longitudinal bore extending therethrough; an insert positionedwithin the bore of the cutting member, the insert including an openingextending therethrough axially aligned with the bore of the cuttingmember, wherein the insert includes an inner surface defining theopening of the insert, wherein at least a portion of the inner surfaceis nonparallel to a central longitudinal axis of a drive shaft, whereinthe inner surface tapers radially outward from the central longitudinalaxis in a distal direction; and a drive shaft extending through thelumen of the outer tubular member, a distal end region of the driveshaft extending into the bore of the cutting member with a distal end ofthe drive shaft abutting a proximal end of the insert, the drive shaftrotatable relative to the outer tubular member to rotate the cuttingmember; wherein the cutting member is fixed to the drive shaft.
 12. Therotational atherectomy device of claim 11, wherein the drive shaftincludes a guidewire lumen extending therethrough axially aligned withthe opening of the insert.
 13. The rotational atherectomy device ofclaim 12, wherein the guidewire lumen has a diameter and the opening ofthe insert has a diameter less than the diameter of the guidewire lumen.14. The rotational atherectomy device of claim 11, wherein the cuttingmember includes a distal opening axially aligned with the opening of theinsert, the distal opening of the cutting member having a diametergreater than or equal to a diameter of the distal opening of the insert.15. The rotational atherectomy device of claim 11, wherein the insertincludes an inner surface defining the opening of the insert, the innersurface having a surface roughness R_(a) of 0.4 micrometers or less. 16.A method of creating or enlarging a passageway through an occlusion in abody lumen, comprising: advancing a guidewire through a body lumen to alocation proximate an occlusion; advancing a rotational atherectomydevice through the body lumen over the guidewire to a location proximalof the occlusion in the body lumen, the rotational atherectomy deviceincluding a rotatable drive shaft extending through an outer tubularmember to rotatably drive a cutting member positioned at a distal end ofthe outer tubular member, and an insert positioned within the cuttingmember, wherein the guidewire extends through an opening of the insertand a guidewire lumen of the drive shaft, wherein the insert includes aninner surface defining the opening of the insert, wherein at least aportion of the inner surface is nonparallel to a central longitudinalaxis of the drive shaft, wherein the inner surface tapers radiallyoutward from the central longitudinal axis in a distal direction; androtating the cutting member relative to the guidewire with the driveshaft while advancing the cutting member through the occlusion, whereinthe cutting member is fixed to the drive shaft.
 17. The method of claim16, wherein a coefficient of static friction between the insert and theguidewire is less than 0.25.